“…This novel approach for protein engineering was extensively expanded in the following years, e.g. for the ligation of uorescent proteins to a protein of interest, [36][37][38] to develop immunoassays with the aim of monitoring glucose levels, 39 to crosslink enzymes, 40 to generate fusion proteins that are inaccessible via direct expression, 41 to form an enzyme cascade within E. coli 42 and to ligate two domains of a protein. 43,44 Other studies focused on the ligation of two peptides [45][46][47] and of a peptide to a protein, [48][49][50][51][52][53] among others to demonstrate the purication of recombinant fusion proteins, 54 to functionalize amyloid-based polymers, 55 to assemble semisynthetic proteins or protein mimics 56,57 and to incorporate functional proteins into hydrogels.…”